[INFO] cloning repository https://github.com/nakakura/tokio_udp_sendrecv_example
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/nakakura/tokio_udp_sendrecv_example" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fnakakura%2Ftokio_udp_sendrecv_example", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fnakakura%2Ftokio_udp_sendrecv_example'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 8a2d2acc59bb69de09d4bbf7552f535d131c016c
[INFO] documenting nakakura/tokio_udp_sendrecv_example against beta-2020-08-29 for beta-1.47-rustdoc-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fnakakura%2Ftokio_udp_sendrecv_example" "/workspace/builds/worker-6/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-6/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/nakakura/tokio_udp_sendrecv_example on toolchain beta-2020-08-29
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2020-08-29" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/nakakura/tokio_udp_sendrecv_example
[INFO] finished tweaking git repo https://github.com/nakakura/tokio_udp_sendrecv_example
[INFO] tweaked toml for git repo https://github.com/nakakura/tokio_udp_sendrecv_example written to /workspace/builds/worker-6/source/Cargo.toml
[INFO] crate git repo https://github.com/nakakura/tokio_udp_sendrecv_example already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2020-08-29" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "rustops/crates-build-env@sha256:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2020-08-29" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 4feca071b7cb42850e44138189a7614edbc47f2235b7691fcee66e9c3de7da71
[INFO] running `Command { std: "docker" "start" "-a" "4feca071b7cb42850e44138189a7614edbc47f2235b7691fcee66e9c3de7da71", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "4feca071b7cb42850e44138189a7614edbc47f2235b7691fcee66e9c3de7da71", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "4feca071b7cb42850e44138189a7614edbc47f2235b7691fcee66e9c3de7da71", kill_on_drop: false }`
[INFO] [stdout] 4feca071b7cb42850e44138189a7614edbc47f2235b7691fcee66e9c3de7da71
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTDOCFLAGS=--cap-lints=warn" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "rustops/crates-build-env@sha256:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2020-08-29" "doc" "--frozen" "--no-deps" "--document-private-items" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] f6b739436f6a9ec417c483fa13be5b651555e3286c64536c36dd830ad397acfa
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "f6b739436f6a9ec417c483fa13be5b651555e3286c64536c36dd830ad397acfa", kill_on_drop: false }`
[INFO] [stderr]     Checking log v0.4.1
[INFO] [stderr]     Checking crossbeam-utils v0.3.2
[INFO] [stderr]     Checking net2 v0.2.32
[INFO] [stderr]     Checking bytes v0.4.7
[INFO] [stderr]     Checking tokio-timer v0.2.3
[INFO] [stderr]     Checking crossbeam-epoch v0.4.1
[INFO] [stderr]     Checking mio v0.6.14
[INFO] [stderr]     Checking tokio-io v0.1.6
[INFO] [stderr]     Checking crossbeam-deque v0.3.1
[INFO] [stderr]     Checking tokio-threadpool v0.1.3
[INFO] [stderr]     Checking tokio-reactor v0.1.1
[INFO] [stderr]     Checking tokio-fs v0.1.0
[INFO] [stderr]     Checking tokio-udp v0.1.0
[INFO] [stderr]     Checking tokio-tcp v0.1.0
[INFO] [stderr]     Checking tokio v0.1.6
[INFO] [stderr]  Documenting udp_sendrecv_tokio v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]  --> src/main.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(drain_filter)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: Compilation failed, aborting rustdoc
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 2 previous errors
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: Could not document `udp_sendrecv_tokio`.
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --crate-type bin --crate-name udp_sendrecv_tokio src/main.rs -o /opt/rustwide/target/doc --error-format=json --json=diagnostic-rendered-ansi --document-private-items -L dependency=/opt/rustwide/target/debug/deps --extern bytes=/opt/rustwide/target/debug/deps/libbytes-20b893f2e4b90079.rmeta --extern futures=/opt/rustwide/target/debug/deps/libfutures-8f66ec0b6a99ab59.rmeta --extern tokio=/opt/rustwide/target/debug/deps/libtokio-7862653fdcc42769.rmeta --extern tokio_io=/opt/rustwide/target/debug/deps/libtokio_io-59236b308e8cc4a8.rmeta --cap-lints=warn --crate-version 0.1.0` (exit code: 1)
[INFO] running `Command { std: "docker" "inspect" "f6b739436f6a9ec417c483fa13be5b651555e3286c64536c36dd830ad397acfa", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "f6b739436f6a9ec417c483fa13be5b651555e3286c64536c36dd830ad397acfa", kill_on_drop: false }`
[INFO] [stdout] f6b739436f6a9ec417c483fa13be5b651555e3286c64536c36dd830ad397acfa